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Understanding I/O
#1
Sorry for the # of questions i'm about to have, but I am not very experienced in electronics and the guy I've been trusting to help on this has been really busy and hasn't read most of the documentation yet. For context; I am working on what is essentially a MIDI keyboard & I want it to have the ability to have variable volume. Based on how this piano will be made, I thought the best way to do this was to take in a signal for each key and measure how long the "note on" signal is recieved in comparison to the base clock. However, based on what I can tell I only have 59 single I/O pins and enough differential I/O pins to take in 9 extra signals (68 signals in total) which is less than the 88 signals I need. So here come the questions.

1. Can I run different I/O types on the same bank?

2. What is this Dual Voltage I/O and how does it work? (Can't find any documentation)

3. What is the Voltage coming out of the LED pins? (Might use them as a way to make out MIDI output)

We have till Saturday morning to get this project done so any help would be really appreciated
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#2
1. Depends on the IO types. Most of the pins on the Au are connected with 3.3V so they are only compatible with IO standards that use 3.3V like LVCMOS33 and TMDS_33.

2. The dual voltage IO allows you power that bank with 1.8V instead of 3.3V. To do this, connect VBSEL (D20) to 1.8V (D21). This allows you to use 1.8V IO standards like LVDS.

3. The LED pins are 3.3V and are like any other pin but with an LED pulling them down (330 ohm resistor + LED). They can still be used as inputs/outputs if you need assuming the LED load isn't an issue.

See https://www.xilinx.com/support/documenta...lectIO.pdf for way more info on IO standards.
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#3
(04-18-2019, 04:48 PM)alchitry Wrote: 1. Depends on the IO types. Most of the pins on the Au are connected with 3.3V so they are only compatible with IO standards that use 3.3V like LVCMOS33 and TMDS_33.

2. The dual voltage IO allows you power that bank with 1.8V instead of 3.3V. To do this, connect VBSEL (D20) to 1.8V (D21). This allows you to use 1.8V IO standards like LVDS.

3. The LED pins are 3.3V and are like any other pin but with an LED pulling them down (330 ohm resistor + LED). They can still be used as inputs/outputs if you need assuming the LED load isn't an issue.

See https://www.xilinx.com/support/documenta...lectIO.pdf for way more info on IO standards.

Thank you for your answers and I did read that pdf before asking and still had these questions. So because i'm not experienced in all of this, do you have any idea how I could read 88 different inputs?
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